9:30 AM - 11:30 AM
[17a-P4-14] Side-chain modification and packing effect in alkylamino aromatic diimide molecules as photoactuator
Keywords:photoactuator
We recently found the photochemical reaction of naphthalene diimides (NDI) having alkylamino side chains in the solid states. Upon irradiation of light (l = 370 nm), the compound 1 showed color change from to yellow to black . This came from the formation of radical anion of 1 as evidenced by UV-Vis-Nir spectroscopy. Furthermore, the crystal 1 showed photomechanical motion.
We suggested that the photomechanical motion of 1 originated from the electrostatic repulsion among 1-1·-, (1)2·-, and 1-1-. If we spatially separate the donor group of NR2 from the acceptor imide moiety by long alkyl chain, van der Waals force would be dominant or interplay with electrostatic interactions. NDI having long alkylamino chain would give an answer as to the question "how long we can separate the donor group of NR2 from core moiety." Solution to these problems has possibilities of controlling photomechanical motion by chemical modification. Here we report synthesis and structure of NDI molecules having long alkylamino chain and their photo-physical property.
We synthesized N,N'-bis(N,N-dialkylamino-yl)naphthalenetetracaboxylic diimide molecules 1-3 by modern method. The condensation reaction of naphthalenetetracaboxylic anhydride with the corresponding diamine was found to be high yield in the presence of DABCO. In the packing of the macrocrystals of 1-3, characteristic X-ray diffraction peak was observed at d ≈3.4 Å, suggesting presence of p- p stacking. However, the crystallinity of 2 was somewhat different from 1 and 3. The powder pattern diffraction of 2 showed complicated peaks as compared with 1 and 3 with weak intensity.
The prepared compounds 1-3 showed photo-response by irradiation at l = 405 nm, though donor groups of NEt2 in 2 and 3 are separated from acceptor imide moiety. Particularly, the radical anion of 2·- was significantly converted from neutral 2 by photo irradiation. We will discuss effect of side-chain modification and packing in these molecules as photoactuator.
We suggested that the photomechanical motion of 1 originated from the electrostatic repulsion among 1-1·-, (1)2·-, and 1-1-. If we spatially separate the donor group of NR2 from the acceptor imide moiety by long alkyl chain, van der Waals force would be dominant or interplay with electrostatic interactions. NDI having long alkylamino chain would give an answer as to the question "how long we can separate the donor group of NR2 from core moiety." Solution to these problems has possibilities of controlling photomechanical motion by chemical modification. Here we report synthesis and structure of NDI molecules having long alkylamino chain and their photo-physical property.
We synthesized N,N'-bis(N,N-dialkylamino-yl)naphthalenetetracaboxylic diimide molecules 1-3 by modern method. The condensation reaction of naphthalenetetracaboxylic anhydride with the corresponding diamine was found to be high yield in the presence of DABCO. In the packing of the macrocrystals of 1-3, characteristic X-ray diffraction peak was observed at d ≈3.4 Å, suggesting presence of p- p stacking. However, the crystallinity of 2 was somewhat different from 1 and 3. The powder pattern diffraction of 2 showed complicated peaks as compared with 1 and 3 with weak intensity.
The prepared compounds 1-3 showed photo-response by irradiation at l = 405 nm, though donor groups of NEt2 in 2 and 3 are separated from acceptor imide moiety. Particularly, the radical anion of 2·- was significantly converted from neutral 2 by photo irradiation. We will discuss effect of side-chain modification and packing in these molecules as photoactuator.